Hybrid multisample/supersample antialiasing

Abstract

The present invention discloses a calculating device configured to shade graphical elements using hybrid antialiasing. A system and method for dynamically adjusting the pixel sampling rate during primitive shading can improve image quality or increase shading performance. Hybrid antialiasing is performed by selecting a number of shaded samples per pixel fragment. A combination of supersample and multisample antialiasing is used where a cluster of sub-pixel samples (multisamples) is processed for each pass through a fragment shader pipeline. The number of shader passes and multisamples in each cluster can be determined dynamically for each primitive based on rendering state.

Description

technical field [0001] Embodiments of the invention generally relate to anti-aliasing techniques in image processing, and more particularly to dynamically adjusting the number of samples shaded in each pixel segment. Background technique [0002] Image processors are often configured to perform antialiasing through multisampling or supersampling. In multisampling, each pixel segment is colored once, and the resulting color value is replicated for all covered subpixel samples. In supersampling, each pixel segment is shaded N times, once for each covered subpixel sample. [0003] Multisampling is useful for anti-aliasing of primitive edges, since what matters here is which samples are covered by incoming primitives. Image textures are usually pre-filtered so that the color values ​​being shaded are of sufficiently low spatial frequency that one shader per pixel is sufficient. However, some effects such as texture alpha transparency and high frequency specular highlights may...

AI Technical Summary

Problems solved by technology

However, since shading is usually the most expensive operation in rendering, shading every sample in a pixel is prohibitively expensive

At the same time, some oversampling implementations need to process the input primitives multiple times, that is, each sub-pixel sample is processed once, which further reduces the efficiency

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